The Specimen Acquisition and Distribution Core will be responsible for obtaining, tracking and allocating blood and tissue samples (colon, ileum, lymph node, plasma and PBMC) for use by the individual projects. The function is critical to the overall development of this PO1 as the Core's support will allow investigators for each of the projects to focus on the generation of preliminary data derived from specimens provided by the Core. The Core will coordinate tissue procurement at Rush University Medical Center (RUMC), University of California-San Francisco (UCSF), and Case Western Reserve University (CWRU), and will oversee distribution of tissue and body fluid samples to Projects 1, 2, and 4. These objectives will be accomplished by implementing an established internet-based communication system to provide real time display of available specimens and an agile online requisition system. All of the routine collection methods are in place at each of the sites of this Core. The ongoing data collection systems established at the sites allow for ready identification of eligible patients who can be scheduled for biopsies within a few weeks. The infrastructure that is in place at UCSF will allow for the efficient and timely identification of unique and rare patients (e.g. elite controllers). Similar systems are in place at the RUMC and CWRU sites for obtaining lymph node and gut tissue samples. In addition to the primary function of the Core in obtaining tissue, the Core will ensure the availability of cryopreserved cells and plasma specimen obtained at each site, and will process and ship the urine specimens needed for the intestinal permeability studies of Project 2. The Core will also obtain relevant clinical information on subjects including current and previous antiretroviral therapy, CD4+ T-cell counts, HIV-1 RNA levels and co-morbid conditions. The overall specific aims for the Core are: 1. Coordinate the timely and efficient acquisition, preparation and transportation of high-quality tissue specimens from the clinical sites at RUMC, UCSF and CWRU to the appropriate project principal investigators. 2. Assure that uniform clinical information is obtained at all clinical sites and that standardized data collection tools are used. 3. Maintain a defined set of standardized data on tissue and cell types, and volumes available for distribution in the repository at all times. 4. Track the collective inventory of viably cryopreserved cells and blood specimens at each participating site for use within the Program project.